1. Field of the Invention
This invention relates to a self-adaptive network array of interactive modules that communicate information to local or central computers, more particularly to fast deployment of new interactive modules in the self-adaptive network array of interactive modules.
2. Background of the Invention
An adaptive network such as wireless sensor networks (WSNs) is a network of interactive modules communicating via wireless links that can self-adapt in accordance with changing transmission conditions. The adaptive network has found applications in fields that require deployment of modules over a wide area for a prolonged time, often operating with constrained power sources. In the adaptive wireless networks, the radio range of each individual interactive module is extended by forwarding messages to neighboring interactive modules which in turn relay the messages to other interactive modules. In many adaptive networks, multiple communication paths are used between the interactive modules and a destination to provide redundancy and reliability of the communication.
The adaptive network does not require that a fixed number of interactive modules be used. New interactive modules may be added to an established adaptive network in order to expand or supplement the coverage of the adaptive network. In conventional methods, the new interactive module is added to an established adaptive network by activating the new interactive module at a candidate location. Wireless messages from the added interactive module are transmitted from the candidate location. If the wireless messages are received by the neighboring interactive modules, the messages are relayed to a base station that manages overall operation of the interactive modules. If the messages are not picked up at the base station, the candidate location is deemed unsuitable and the new interactive module is moved to another location to repeat the same process of transmitting the messages and monitoring the messages at the base station. Because multiple hops may be needed before reaching the base station, it may take a prolonged time before confirming whether the candidate location is suitable for deployment of the new interactive module.
Adding new interactive modules to the adaptive network is complicated by the fact that some interactive modules remain in a sleep mode for most of the time to conserve power. The interactive modules in the adaptive network (especially wireless sensor networks) operate on constrained energy sources such as batteries or solar panels. Therefore, to conserve power, the interactive modules become fully operation for a brief wake-up period before reverting to a sleep-mode to conserve power. Such intermittent operation means that the interactive modules already deployed in the adaptive network may not be always available to receive and relay the messages from the newly deployed interactive modules to the base station. Moreover, when one or more hops between already deployed interactive modules are needed, each interactive module must wait for the next interactive module to wake up before relaying the messages to the next interactive module. Therefore, the sleep mode of the interactive modules causes further delays and inconveniences in the deployment of new interactive modules.